workbench/libs/png/pngpriv.h

   1
   2 /* pngpriv.h - private declarations for use inside libpng
   3  *
   4  * For conditions of distribution and use, see copyright notice in png.h
   5  * Copyright (c) 1998-2012 Glenn Randers-Pehrson
   6  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
   7  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
   8  *
   9  * Last changed in libpng 1.5.10 [March 29, 2012]
  10  *
  11  * This code is released under the libpng license.
  12  * For conditions of distribution and use, see the disclaimer
  13  * and license in png.h
  14  */
  15
  16 /* The symbols declared in this file (including the functions declared
  17  * as PNG_EXTERN) are PRIVATE.  They are not part of the libpng public
  18  * interface, and are not recommended for use by regular applications.
  19  * Some of them may become public in the future; others may stay private,
  20  * change in an incompatible way, or even disappear.
  21  * Although the libpng users are not forbidden to include this header,
  22  * they should be well aware of the issues that may arise from doing so.
  23  */
  24
  25 #ifndef PNGPRIV_H
  26 #define PNGPRIV_H
  27
  28 /* Feature Test Macros.  The following are defined here to ensure that correctly
  29  * implemented libraries reveal the APIs libpng needs to build and hide those
  30  * that are not needed and potentially damaging to the compilation.
  31  *
  32  * Feature Test Macros must be defined before any system header is included (see
  33  * POSIX 1003.1 2.8.2 "POSIX Symbols."
  34  *
  35  * These macros only have an effect if the operating system supports either
  36  * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
  37  * Windows/Visual Studio) there is no effect; the OS specific tests below are
  38  * still required (as of 2011-05-02.)
  39  */
  40 #define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
  41
  42 /* This is required for the definition of abort(), used as a last ditch
  43  * error handler when all else fails.
  44  */
  45 #include <stdlib.h>
  46
  47 /* This is used to find 'offsetof', used below for alignment tests. */
  48 #include <stddef.h>
  49
  50 #define PNGLIB_BUILD /*libpng is being built, not used*/
  51
  52 #ifdef PNG_USER_CONFIG
  53 #  include "pngusr.h"
  54    /* These should have been defined in pngusr.h */
  55 #  ifndef PNG_USER_PRIVATEBUILD
  56 #    define PNG_USER_PRIVATEBUILD "Custom libpng build"
  57 #  endif
  58 #  ifndef PNG_USER_DLLFNAME_POSTFIX
  59 #    define PNG_USER_DLLFNAME_POSTFIX "Cb"
  60 #  endif
  61 #endif
  62
  63 /* Is this a build of a DLL where compilation of the object modules requires
  64  * different preprocessor settings to those required for a simple library?  If
  65  * so PNG_BUILD_DLL must be set.
  66  *
  67  * If libpng is used inside a DLL but that DLL does not export the libpng APIs
  68  * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
  69  * static library of libpng then link the DLL against that.
  70  */
  71 #ifndef PNG_BUILD_DLL
  72 #  ifdef DLL_EXPORT
  73       /* This is set by libtool when files are compiled for a DLL; libtool
  74        * always compiles twice, even on systems where it isn't necessary.  Set
  75        * PNG_BUILD_DLL in case it is necessary:
  76        */
  77 #     define PNG_BUILD_DLL
  78 #  else
  79 #     ifdef _WINDLL
  80          /* This is set by the Microsoft Visual Studio IDE in projects that
  81           * build a DLL.  It can't easily be removed from those projects (it
  82           * isn't visible in the Visual Studio UI) so it is a fairly reliable
  83           * indication that PNG_IMPEXP needs to be set to the DLL export
  84           * attributes.
  85           */
  86 #        define PNG_BUILD_DLL
  87 #     else
  88 #        ifdef __DLL__
  89             /* This is set by the Borland C system when compiling for a DLL
  90              * (as above.)
  91              */
  92 #           define PNG_BUILD_DLL
  93 #        else
  94             /* Add additional compiler cases here. */
  95 #        endif
  96 #     endif
  97 #  endif
  98 #endif /* Setting PNG_BUILD_DLL if required */
  99
 100 /* See pngconf.h for more details: the builder of the library may set this on
 101  * the command line to the right thing for the specific compilation system or it
 102  * may be automagically set above (at present we know of no system where it does
 103  * need to be set on the command line.)
 104  *
 105  * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
 106  * setting it to the "import" setting for a DLL build.
 107  */
 108 #ifndef PNG_IMPEXP
 109 #  ifdef PNG_BUILD_DLL
 110 #     define PNG_IMPEXP PNG_DLL_EXPORT
 111 #  else
 112       /* Not building a DLL, or the DLL doesn't require specific export
 113        * definitions.
 114        */
 115 #     define PNG_IMPEXP
 116 #  endif
 117 #endif
 118
 119 /* No warnings for private or deprecated functions in the build: */
 120 #ifndef PNG_DEPRECATED
 121 #  define PNG_DEPRECATED
 122 #endif
 123 #ifndef PNG_PRIVATE
 124 #  define PNG_PRIVATE
 125 #endif
 126
 127 #include "png.h"
 128 #include "pnginfo.h"
 129 #include "pngstruct.h"
 130
 131 /* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
 132 #ifndef PNG_DLL_EXPORT
 133 #  define PNG_DLL_EXPORT
 134 #endif
 135
 136 /* SECURITY and SAFETY:
 137  *
 138  * By default libpng is built without any internal limits on image size,
 139  * individual heap (png_malloc) allocations or the total amount of memory used.
 140  * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
 141  * (unless individually overridden).  These limits are believed to be fairly
 142  * safe, but builders of secure systems should verify the values against the
 143  * real system capabilities.
 144  */
 145
 146 #ifdef PNG_SAFE_LIMITS_SUPPORTED
 147    /* 'safe' limits */
 148 #  ifndef PNG_USER_WIDTH_MAX
 149 #     define PNG_USER_WIDTH_MAX 1000000
 150 #  endif
 151 #  ifndef PNG_USER_HEIGHT_MAX
 152 #     define PNG_USER_HEIGHT_MAX 1000000
 153 #  endif
 154 #  ifndef PNG_USER_CHUNK_CACHE_MAX
 155 #     define PNG_USER_CHUNK_CACHE_MAX 128
 156 #  endif
 157 #  ifndef PNG_USER_CHUNK_MALLOC_MAX
 158 #     define PNG_USER_CHUNK_MALLOC_MAX 8000000
 159 #  endif
 160 #else
 161    /* values for no limits */
 162 #  ifndef PNG_USER_WIDTH_MAX
 163 #     define PNG_USER_WIDTH_MAX 0x7fffffff
 164 #  endif
 165 #  ifndef PNG_USER_HEIGHT_MAX
 166 #     define PNG_USER_HEIGHT_MAX 0x7fffffff
 167 #  endif
 168 #  ifndef PNG_USER_CHUNK_CACHE_MAX
 169 #     define PNG_USER_CHUNK_CACHE_MAX 0
 170 #  endif
 171 #  ifndef PNG_USER_CHUNK_MALLOC_MAX
 172 #     define PNG_USER_CHUNK_MALLOC_MAX 0
 173 #  endif
 174 #endif
 175
 176 /* This is used for 16 bit gamma tables - only the top level pointers are const,
 177  * this could be changed:
 178  */
 179 typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 180
 181 /* Added at libpng-1.2.9 */
 182 /* Moved to pngpriv.h at libpng-1.5.0 */
 183
 184 /* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure"
 185  * script.  We may need it here to get the correct configuration on things
 186  * like limits.
 187  */
 188 #ifdef PNG_CONFIGURE_LIBPNG
 189 #  ifdef HAVE_CONFIG_H
 190 #    include "config.h"
 191 #  endif
 192 #endif
 193
 194 /* Moved to pngpriv.h at libpng-1.5.0 */
 195 /* NOTE: some of these may have been used in external applications as
 196  * these definitions were exposed in pngconf.h prior to 1.5.
 197  */
 198
 199 /* If you are running on a machine where you cannot allocate more
 200  * than 64K of memory at once, uncomment this.  While libpng will not
 201  * normally need that much memory in a chunk (unless you load up a very
 202  * large file), zlib needs to know how big of a chunk it can use, and
 203  * libpng thus makes sure to check any memory allocation to verify it
 204  * will fit into memory.
 205  *
 206  * zlib provides 'MAXSEG_64K' which, if defined, indicates the
 207  * same limit and pngconf.h (already included) sets the limit
 208  * if certain operating systems are detected.
 209  */
 210 #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
 211 #  define PNG_MAX_MALLOC_64K
 212 #endif
 213
 214 #ifndef PNG_UNUSED
 215 /* Unused formal parameter warnings are silenced using the following macro
 216  * which is expected to have no bad effects on performance (optimizing
 217  * compilers will probably remove it entirely).  Note that if you replace
 218  * it with something other than whitespace, you must include the terminating
 219  * semicolon.
 220  */
 221 #  define PNG_UNUSED(param) (void)param;
 222 #endif
 223
 224 /* Just a little check that someone hasn't tried to define something
 225  * contradictory.
 226  */
 227 #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
 228 #  undef PNG_ZBUF_SIZE
 229 #  define PNG_ZBUF_SIZE 65536L
 230 #endif
 231
 232 /* PNG_STATIC is used to mark internal file scope functions if they need to be
 233  * accessed for implementation tests (see the code in tests/?*).
 234  */
 235 #ifndef PNG_STATIC
 236 #   define PNG_STATIC static
 237 #endif
 238
 239 /* C99 restrict is used where possible, to do this 'restrict' is defined as
 240  * empty if we can't be sure it is supported.  configure builds have already
 241  * done this work.
 242  */
 243 #ifdef PNG_CONFIGURE_LIBPNG
 244 #  define PNG_RESTRICT restrict
 245 #else
 246    /* Modern compilers support restrict, but assume not for anything not
 247     * recognized here:
 248     */
 249 #  if defined __GNUC__ || defined _MSC_VER || defined __WATCOMC__
 250 #     define PNG_RESTRICT restrict
 251 #  else
 252 #     define PNG_RESTRICT
 253 #  endif
 254 #endif
 255
 256 /* If warnings or errors are turned off the code is disabled or redirected here.
 257  * From 1.5.4 functions have been added to allow very limited formatting of
 258  * error and warning messages - this code will also be disabled here.
 259  */
 260 #ifdef PNG_WARNINGS_SUPPORTED
 261 #  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
 262 #else
 263 #  define png_warning(s1,s2) ((void)(s1))
 264 #  define png_chunk_warning(s1,s2) ((void)(s1))
 265 #  define png_warning_parameter(p,number,string) ((void)0)
 266 #  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
 267 #  define png_warning_parameter_signed(p,number,format,value) ((void)0)
 268 #  define png_formatted_warning(pp,p,message) ((void)(pp))
 269 #  define PNG_WARNING_PARAMETERS(p)
 270 #endif
 271 #ifndef PNG_ERROR_TEXT_SUPPORTED
 272 #  define png_error(s1,s2) png_err(s1)
 273 #  define png_chunk_error(s1,s2) png_err(s1)
 274 #  define png_fixed_error(s1,s2) png_err(s1)
 275 #endif
 276
 277 /* C allows up-casts from (void*) to any pointer and (const void*) to any
 278  * pointer to a const object.  C++ regards this as a type error and requires an
 279  * explicit, static, cast and provides the static_cast<> rune to ensure that
 280  * const is not cast away.
 281  */
 282 #ifdef __cplusplus
 283 #  define png_voidcast(type, value) static_cast<type>(value)
 284 #else
 285 #  define png_voidcast(type, value) (value)
 286 #endif /* __cplusplus */
 287
 288 #ifndef PNG_EXTERN
 289 /* The functions exported by PNG_EXTERN are internal functions, which
 290  * aren't usually used outside the library (as far as I know), so it is
 291  * debatable if they should be exported at all.  In the future, when it
 292  * is possible to have run-time registry of chunk-handling functions,
 293  * some of these might be made available again.
 294  *
 295  * 1.5.7: turned the use of 'extern' back on, since it is localized to pngpriv.h
 296  * it should be safe now (it is unclear why it was turned off.)
 297  */
 298 #  define PNG_EXTERN extern
 299 #endif
 300
 301 /* Some fixed point APIs are still required even if not exported because
 302  * they get used by the corresponding floating point APIs.  This magic
 303  * deals with this:
 304  */
 305 #ifdef PNG_FIXED_POINT_SUPPORTED
 306 #  define PNGFAPI PNGAPI
 307 #else
 308 #  define PNGFAPI /* PRIVATE */
 309 #endif
 310
 311 /* Other defines specific to compilers can go here.  Try to keep
 312  * them inside an appropriate ifdef/endif pair for portability.
 313  */
 314 #if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
 315     defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
 316    /* png.c requires the following ANSI-C constants if the conversion of
 317     * floating point to ASCII is implemented therein:
 318     *
 319     *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
 320     *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
 321     *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
 322     */
 323 #  include <float.h>
 324
 325 #  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
 326     defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
 327      /* We need to check that <math.h> hasn't already been included earlier
 328       * as it seems it doesn't agree with <fp.h>, yet we should really use
 329       * <fp.h> if possible.
 330       */
 331 #    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
 332 #      include <fp.h>
 333 #    endif
 334 #  else
 335 #    include <math.h>
 336 #  endif
 337 #  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
 338      /* Amiga SAS/C: We must include builtin FPU functions when compiling using
 339       * MATH=68881
 340       */
 341 #    include <m68881.h>
 342 #  endif
 343 #endif
 344
 345 /* This provides the non-ANSI (far) memory allocation routines. */
 346 #if defined(__TURBOC__) && defined(__MSDOS__)
 347 #  include <mem.h>
 348 #  include <alloc.h>
 349 #endif
 350
 351 #if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
 352     defined(_WIN32) || defined(__WIN32__)
 353 #  include <windows.h>  /* defines _WINDOWS_ macro */
 354 #endif
 355
 356 /* Moved here around 1.5.0beta36 from pngconf.h */
 357 /* Users may want to use these so they are not private.  Any library
 358  * functions that are passed far data must be model-independent.
 359  */
 360
 361 /* Memory model/platform independent fns */
 362 #ifndef PNG_ABORT
 363 #  ifdef _WINDOWS_
 364 #    define PNG_ABORT() ExitProcess(0)
 365 #  else
 366 #    define PNG_ABORT() abort()
 367 #  endif
 368 #endif
 369
 370 #ifdef USE_FAR_KEYWORD
 371 /* Use this to make far-to-near assignments */
 372 #  define CHECK   1
 373 #  define NOCHECK 0
 374 #  define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
 375 #  define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
 376 #  define png_strlen  _fstrlen
 377 #  define png_memcmp  _fmemcmp    /* SJT: added */
 378 #  define png_memcpy  _fmemcpy
 379 #  define png_memset  _fmemset
 380 #else
 381 #  ifdef _WINDOWS_  /* Favor Windows over C runtime fns */
 382 #    define CVT_PTR(ptr)         (ptr)
 383 #    define CVT_PTR_NOCHECK(ptr) (ptr)
 384 #    define png_strlen  lstrlenA
 385 #    define png_memcmp  memcmp
 386 #    define png_memcpy  CopyMemory
 387 #    define png_memset  memset
 388 #  else
 389 #    define CVT_PTR(ptr)         (ptr)
 390 #    define CVT_PTR_NOCHECK(ptr) (ptr)
 391 #    define png_strlen  strlen
 392 #    define png_memcmp  memcmp      /* SJT: added */
 393 #    define png_memcpy  memcpy
 394 #    define png_memset  memset
 395 #  endif
 396 #endif
 397
 398 /* These macros may need to be architecture dependent. */
 399 #define PNG_ALIGN_NONE   0 /* do not use data alignment */
 400 #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
 401 #ifdef offsetof
 402 #  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
 403 #else
 404 #  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
 405 #endif
 406 #define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
 407
 408 #ifndef PNG_ALIGN_TYPE
 409    /* Default to using aligned access optimizations and requiring alignment to a
 410     * multiple of the data type size.  Override in a compiler specific fashion
 411     * if necessary by inserting tests here:
 412     */
 413 #  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
 414 #endif
 415
 416 #if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
 417    /* This is used because in some compiler implementations non-aligned
 418     * structure members are supported, so the offsetof approach below fails.
 419     * Set PNG_ALIGN_TO_SIZE=0 for compiler combinations where unaligned access
 420     * is good for performance.  Do not do this unless you have tested the result
 421     * and understand it.
 422     */
 423 #  define png_alignof(type) (sizeof (type))
 424 #else
 425 #  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
 426 #     define png_alignof(type) offsetof(struct{char c; type t;}, t)
 427 #  else
 428 #     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
 429 #        define png_alignof(type) (1)
 430 #     endif
 431       /* Else leave png_alignof undefined to prevent use thereof */
 432 #  endif
 433 #endif
 434
 435 /* This implicitly assumes alignment is always to a power of 2. */
 436 #ifdef png_alignof
 437 #  define png_isaligned(ptr, type)\
 438    ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
 439 #else
 440 #  define png_isaligned(ptr, type) 0
 441 #endif
 442
 443 /* End of memory model/platform independent support */
 444 /* End of 1.5.0beta36 move from pngconf.h */
 445
 446 /* CONSTANTS and UTILITY MACROS
 447  * These are used internally by libpng and not exposed in the API
 448  */
 449
 450 /* Various modes of operation.  Note that after an init, mode is set to
 451  * zero automatically when the structure is created.  Three of these
 452  * are defined in png.h because they need to be visible to applications
 453  * that call png_set_unknown_chunk().
 454  */
 455 /* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
 456 /* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
 457 #define PNG_HAVE_IDAT               0x04
 458 /* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
 459 #define PNG_HAVE_IEND               0x10
 460 #define PNG_HAVE_gAMA               0x20
 461 #define PNG_HAVE_cHRM               0x40
 462 #define PNG_HAVE_sRGB               0x80
 463 #define PNG_HAVE_CHUNK_HEADER      0x100
 464 #define PNG_WROTE_tIME             0x200
 465 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
 466 #define PNG_BACKGROUND_IS_GRAY     0x800
 467 #define PNG_HAVE_PNG_SIGNATURE    0x1000
 468 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
 469 #define PNG_HAVE_iCCP             0x4000
 470
 471 /* Flags for the transformations the PNG library does on the image data */
 472 #define PNG_BGR                 0x0001
 473 #define PNG_INTERLACE           0x0002
 474 #define PNG_PACK                0x0004
 475 #define PNG_SHIFT               0x0008
 476 #define PNG_SWAP_BYTES          0x0010
 477 #define PNG_INVERT_MONO         0x0020
 478 #define PNG_QUANTIZE            0x0040
 479 #define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
 480 #define PNG_BACKGROUND_EXPAND   0x0100
 481 #define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
 482 #define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
 483 #define PNG_RGBA                0x0800
 484 #define PNG_EXPAND              0x1000
 485 #define PNG_GAMMA               0x2000
 486 #define PNG_GRAY_TO_RGB         0x4000
 487 #define PNG_FILLER              0x8000
 488 #define PNG_PACKSWAP           0x10000
 489 #define PNG_SWAP_ALPHA         0x20000
 490 #define PNG_STRIP_ALPHA        0x40000
 491 #define PNG_INVERT_ALPHA       0x80000
 492 #define PNG_USER_TRANSFORM    0x100000
 493 #define PNG_RGB_TO_GRAY_ERR   0x200000
 494 #define PNG_RGB_TO_GRAY_WARN  0x400000
 495 #define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
 496 #define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
 497 #define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
 498 #define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
 499 #define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
 500                        /*   0x8000000 unused */
 501                        /*  0x10000000 unused */
 502                        /*  0x20000000 unused */
 503                        /*  0x40000000 unused */
 504 /* Flags for png_create_struct */
 505 #define PNG_STRUCT_PNG   0x0001
 506 #define PNG_STRUCT_INFO  0x0002
 507
 508 /* Scaling factor for filter heuristic weighting calculations */
 509 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
 510 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
 511
 512 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
 513 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
 514 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
 515 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
 516 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
 517 #define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
 518 #define PNG_FLAG_ZLIB_FINISHED            0x0020
 519 #define PNG_FLAG_ROW_INIT                 0x0040
 520 #define PNG_FLAG_FILLER_AFTER             0x0080
 521 #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
 522 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
 523 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
 524 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
 525 #define PNG_FLAG_ASSUME_sRGB              0x1000  /* Added to libpng-1.5.4 */
 526 #define PNG_FLAG_OPTIMIZE_ALPHA           0x2000  /* Added to libpng-1.5.4 */
 527 #define PNG_FLAG_DETECT_UNINITIALIZED     0x4000  /* Added to libpng-1.5.4 */
 528 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000
 529 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000
 530 #define PNG_FLAG_LIBRARY_MISMATCH         0x20000
 531 #define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000
 532 #define PNG_FLAG_STRIP_ERROR_TEXT         0x80000
 533 #define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000
 534                                   /*      0x200000  unused */
 535                                   /*      0x400000  unused */
 536 #define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000  /* Added to libpng-1.4.0 */
 537 #define PNG_FLAG_ZTXT_CUSTOM_STRATEGY    0x1000000  /* 5 lines added */
 538 #define PNG_FLAG_ZTXT_CUSTOM_LEVEL       0x2000000  /* to libpng-1.5.4 */
 539 #define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL   0x4000000
 540 #define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000
 541 #define PNG_FLAG_ZTXT_CUSTOM_METHOD      0x10000000
 542                                   /*     0x20000000  unused */
 543                                   /*     0x40000000  unused */
 544
 545 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
 546                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
 547
 548 #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
 549                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
 550
 551 #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
 552                                      PNG_FLAG_CRC_CRITICAL_MASK)
 553
 554 /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
 555  * can handle at once.  This type need be no larger than 16 bits (so maximum of
 556  * 65535), this define allows us to discover how big it is, but limited by the
 557  * maximuum for png_size_t.  The value can be overriden in a library build
 558  * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
 559  * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
 560  * and may even improve performance on some systems (and degrade it on others.)
 561  */
 562 #ifndef ZLIB_IO_MAX
 563 #  define ZLIB_IO_MAX ((uInt)-1)
 564 #endif
 565
 566 /* Save typing and make code easier to understand */
 567
 568 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
 569    abs((int)((c1).green) - (int)((c2).green)) + \
 570    abs((int)((c1).blue) - (int)((c2).blue)))
 571
 572 /* Added to libpng-1.2.6 JB */
 573 #define PNG_ROWBYTES(pixel_bits, width) \
 574     ((pixel_bits) >= 8 ? \
 575     ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
 576     (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
 577
 578 /* PNG_OUT_OF_RANGE returns true if value is outside the range
 579  * ideal-delta..ideal+delta.  Each argument is evaluated twice.
 580  * "ideal" and "delta" should be constants, normally simple
 581  * integers, "value" a variable. Added to libpng-1.2.6 JB
 582  */
 583 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
 584    ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
 585
 586 /* Conversions between fixed and floating point, only defined if
 587  * required (to make sure the code doesn't accidentally use float
 588  * when it is supposedly disabled.)
 589  */
 590 #ifdef PNG_FLOATING_POINT_SUPPORTED
 591 /* The floating point conversion can't overflow, though it can and
 592  * does lose accuracy relative to the original fixed point value.
 593  * In practice this doesn't matter because png_fixed_point only
 594  * stores numbers with very low precision.  The png_ptr and s
 595  * arguments are unused by default but are there in case error
 596  * checking becomes a requirement.
 597  */
 598 #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
 599
 600 /* The fixed point conversion performs range checking and evaluates
 601  * its argument multiple times, so must be used with care.  The
 602  * range checking uses the PNG specification values for a signed
 603  * 32 bit fixed point value except that the values are deliberately
 604  * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
 605  * (2^31-1) * 100000). 's' is a string that describes the value being
 606  * converted.
 607  *
 608  * NOTE: this macro will raise a png_error if the range check fails,
 609  * therefore it is normally only appropriate to use this on values
 610  * that come from API calls or other sources where an out of range
 611  * error indicates a programming error, not a data error!
 612  *
 613  * NOTE: by default this is off - the macro is not used - because the
 614  * function call saves a lot of code.
 615  */
 616 #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
 617 #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
 618     ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
 619 #else
 620 PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp,
 621    png_const_charp text));
 622 #endif
 623 #endif
 624
 625 /* Constants for known chunk types.  If you need to add a chunk, define the name
 626  * here.  For historical reasons these constants have the form png_<name>; i.e.
 627  * the prefix is lower case.  Please use decimal values as the parameters to
 628  * match the ISO PNG specification and to avoid relying on the C locale
 629  * interpretation of character values.
 630  *
 631  * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
 632  * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
 633  * to be generated if required.
 634  *
 635  * PNG_32b correctly produces a value shifted by up to 24 bits, even on
 636  * architectures where (int) is only 16 bits.
 637  */
 638 #define PNG_32b(b,s) ((png_uint_32)(b) << (s))
 639 #define PNG_CHUNK(b1,b2,b3,b4) \
 640    (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
 641
 642 #define png_IHDR PNG_CHUNK( 73,  72,  68,  82)
 643 #define png_IDAT PNG_CHUNK( 73,  68,  65,  84)
 644 #define png_IEND PNG_CHUNK( 73,  69,  78,  68)
 645 #define png_PLTE PNG_CHUNK( 80,  76,  84,  69)
 646 #define png_bKGD PNG_CHUNK( 98,  75,  71,  68)
 647 #define png_cHRM PNG_CHUNK( 99,  72,  82,  77)
 648 #define png_gAMA PNG_CHUNK(103,  65,  77,  65)
 649 #define png_hIST PNG_CHUNK(104,  73,  83,  84)
 650 #define png_iCCP PNG_CHUNK(105,  67,  67,  80)
 651 #define png_iTXt PNG_CHUNK(105,  84,  88, 116)
 652 #define png_oFFs PNG_CHUNK(111,  70,  70, 115)
 653 #define png_pCAL PNG_CHUNK(112,  67,  65,  76)
 654 #define png_sCAL PNG_CHUNK(115,  67,  65,  76)
 655 #define png_pHYs PNG_CHUNK(112,  72,  89, 115)
 656 #define png_sBIT PNG_CHUNK(115,  66,  73,  84)
 657 #define png_sPLT PNG_CHUNK(115,  80,  76,  84)
 658 #define png_sRGB PNG_CHUNK(115,  82,  71,  66)
 659 #define png_sTER PNG_CHUNK(115,  84,  69,  82)
 660 #define png_tEXt PNG_CHUNK(116,  69,  88, 116)
 661 #define png_tIME PNG_CHUNK(116,  73,  77,  69)
 662 #define png_tRNS PNG_CHUNK(116,  82,  78,  83)
 663 #define png_zTXt PNG_CHUNK(122,  84,  88, 116)
 664
 665 /* The following will work on (signed char*) strings, whereas the get_uint_32
 666  * macro will fail on top-bit-set values because of the sign extension.
 667  */
 668 #define PNG_CHUNK_FROM_STRING(s)\
 669    PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
 670
 671 /* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
 672  * signed and the argument is a (char[])  This macro will fail miserably on
 673  * systems where (char) is more than 8 bits.
 674  */
 675 #define PNG_STRING_FROM_CHUNK(s,c)\
 676    (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
 677    ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
 678
 679 /* Do the same but terminate with a null character. */
 680 #define PNG_CSTRING_FROM_CHUNK(s,c)\
 681    (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
 682
 683 /* Test on flag values as defined in the spec (section 5.4): */
 684 #define PNG_CHUNK_ANCILLIARY(c)   (1 & ((c) >> 29))
 685 #define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLIARY(c))
 686 #define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
 687 #define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
 688 #define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
 689
 690 /* Gamma values (new at libpng-1.5.4): */
 691 #define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
 692 #define PNG_GAMMA_MAC_INVERSE 65909
 693 #define PNG_GAMMA_sRGB_INVERSE 45455
 694
 695
 696 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
 697 #ifdef __cplusplus
 698 extern "C" {
 699 #endif /* __cplusplus */
 700
 701 /* These functions are used internally in the code.  They generally
 702  * shouldn't be used unless you are writing code to add or replace some
 703  * functionality in libpng.  More information about most functions can
 704  * be found in the files where the functions are located.
 705  */
 706
 707 /* Check the user version string for compatibility, returns false if the version
 708  * numbers aren't compatible.
 709  */
 710 PNG_EXTERN int png_user_version_check(png_structp png_ptr,
 711    png_const_charp user_png_ver);
 712
 713 /* Allocate memory for an internal libpng struct */
 714 PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
 715    PNG_ALLOCATED);
 716
 717 /* Free memory from internal libpng struct */
 718 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
 719
 720 PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct_2,
 721    PNGARG((int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)),
 722    PNG_ALLOCATED);
 723 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
 724     png_free_ptr free_fn, png_voidp mem_ptr));
 725
 726 /* Free any memory that info_ptr points to and reset struct. */
 727 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
 728     png_infop info_ptr));
 729
 730 /* Function to allocate memory for zlib.  PNGAPI is disallowed. */
 731 PNG_EXTERN PNG_FUNCTION(voidpf,png_zalloc,PNGARG((voidpf png_ptr, uInt items,
 732    uInt size)),PNG_ALLOCATED);
 733
 734 /* Function to free memory for zlib.  PNGAPI is disallowed. */
 735 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
 736
 737 /* Next four functions are used internally as callbacks.  PNGCBAPI is required
 738  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
 739  * PNGCBAPI at 1.5.0
 740  */
 741
 742 PNG_EXTERN void PNGCBAPI png_default_read_data PNGARG((png_structp png_ptr,
 743     png_bytep data, png_size_t length));
 744
 745 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 746 PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
 747     png_bytep buffer, png_size_t length));
 748 #endif
 749
 750 PNG_EXTERN void PNGCBAPI png_default_write_data PNGARG((png_structp png_ptr,
 751     png_bytep data, png_size_t length));
 752
 753 #ifdef PNG_WRITE_FLUSH_SUPPORTED
 754 #  ifdef PNG_STDIO_SUPPORTED
 755 PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr));
 756 #  endif
 757 #endif
 758
 759 /* Reset the CRC variable */
 760 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
 761
 762 /* Write the "data" buffer to whatever output you are using */
 763 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr,
 764     png_const_bytep data, png_size_t length));
 765
 766 /* Read and check the PNG file signature */
 767 PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr));
 768
 769 /* Read the chunk header (length + type name) */
 770 PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
 771
 772 /* Read data from whatever input you are using into the "data" buffer */
 773 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
 774     png_size_t length));
 775
 776 /* Read bytes into buf, and update png_ptr->crc */
 777 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
 778     png_size_t length));
 779
 780 /* Decompress data in a chunk that uses compression */
 781 #if defined(PNG_READ_COMPRESSED_TEXT_SUPPORTED)
 782 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
 783     int comp_type, png_size_t chunklength, png_size_t prefix_length,
 784     png_size_t *data_length));
 785 #endif
 786
 787 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
 788 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
 789
 790 /* Read the CRC from the file and compare it to the libpng calculated CRC */
 791 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
 792
 793 /* Calculate the CRC over a section of data.  Note that we are only
 794  * passing a maximum of 64K on systems that have this as a memory limit,
 795  * since this is the maximum buffer size we can specify.
 796  */
 797 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr,
 798     png_const_bytep ptr, png_size_t length));
 799
 800 #ifdef PNG_WRITE_FLUSH_SUPPORTED
 801 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
 802 #endif
 803
 804 /* Write various chunks */
 805
 806 /* Write the IHDR chunk, and update the png_struct with the necessary
 807  * information.
 808  */
 809 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
 810     png_uint_32 height,
 811     int bit_depth, int color_type, int compression_method, int filter_method,
 812     int interlace_method));
 813
 814 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr,
 815     png_const_colorp palette, png_uint_32 num_pal));
 816
 817 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
 818     png_size_t length));
 819
 820 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
 821
 822 #ifdef PNG_WRITE_gAMA_SUPPORTED
 823 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 824 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
 825 #  endif
 826 #  ifdef PNG_FIXED_POINT_SUPPORTED
 827 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
 828     png_fixed_point file_gamma));
 829 #  endif
 830 #endif
 831
 832 #ifdef PNG_WRITE_sBIT_SUPPORTED
 833 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr,
 834     png_const_color_8p sbit, int color_type));
 835 #endif
 836
 837 #ifdef PNG_WRITE_cHRM_SUPPORTED
 838 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 839 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
 840     double white_x, double white_y,
 841     double red_x, double red_y, double green_x, double green_y,
 842     double blue_x, double blue_y));
 843 #  endif
 844 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
 845     png_fixed_point int_white_x, png_fixed_point int_white_y,
 846     png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
 847     int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
 848     png_fixed_point int_blue_y));
 849 #endif
 850
 851 #ifdef PNG_WRITE_sRGB_SUPPORTED
 852 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
 853     int intent));
 854 #endif
 855
 856 #ifdef PNG_WRITE_iCCP_SUPPORTED
 857 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
 858     png_const_charp name, int compression_type,
 859     png_const_charp profile, int proflen));
 860    /* Note to maintainer: profile should be png_bytep */
 861 #endif
 862
 863 #ifdef PNG_WRITE_sPLT_SUPPORTED
 864 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
 865     png_const_sPLT_tp palette));
 866 #endif
 867
 868 #ifdef PNG_WRITE_tRNS_SUPPORTED
 869 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr,
 870     png_const_bytep trans, png_const_color_16p values, int number,
 871     int color_type));
 872 #endif
 873
 874 #ifdef PNG_WRITE_bKGD_SUPPORTED
 875 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
 876     png_const_color_16p values, int color_type));
 877 #endif
 878
 879 #ifdef PNG_WRITE_hIST_SUPPORTED
 880 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr,
 881     png_const_uint_16p hist, int num_hist));
 882 #endif
 883
 884 /* Chunks that have keywords */
 885 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
 886     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
 887 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
 888     png_const_charp key, png_charpp new_key));
 889 #endif
 890
 891 #ifdef PNG_WRITE_tEXt_SUPPORTED
 892 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_const_charp key,
 893     png_const_charp text, png_size_t text_len));
 894 #endif
 895
 896 #ifdef PNG_WRITE_zTXt_SUPPORTED
 897 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_const_charp key,
 898     png_const_charp text, png_size_t text_len, int compression));
 899 #endif
 900
 901 #ifdef PNG_WRITE_iTXt_SUPPORTED
 902 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
 903     int compression, png_const_charp key, png_const_charp lang,
 904     png_const_charp lang_key, png_const_charp text));
 905 #endif
 906
 907 #ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
 908 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
 909     png_infop info_ptr, png_const_textp text_ptr, int num_text));
 910 #endif
 911
 912 #ifdef PNG_WRITE_oFFs_SUPPORTED
 913 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
 914     png_int_32 x_offset, png_int_32 y_offset, int unit_type));
 915 #endif
 916
 917 #ifdef PNG_WRITE_pCAL_SUPPORTED
 918 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
 919     png_int_32 X0, png_int_32 X1, int type, int nparams,
 920     png_const_charp units, png_charpp params));
 921 #endif
 922
 923 #ifdef PNG_WRITE_pHYs_SUPPORTED
 924 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
 925     png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
 926     int unit_type));
 927 #endif
 928
 929 #ifdef PNG_WRITE_tIME_SUPPORTED
 930 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
 931     png_const_timep mod_time));
 932 #endif
 933
 934 #ifdef PNG_WRITE_sCAL_SUPPORTED
 935 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
 936     int unit, png_const_charp width, png_const_charp height));
 937 #endif
 938
 939 /* Called when finished processing a row of data */
 940 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
 941
 942 /* Internal use only.   Called before first row of data */
 943 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
 944
 945 /* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
 946  * array of png_ptr->width pixels.  If the image is not interlaced or this
 947  * is the final pass this just does a png_memcpy, otherwise the "display" flag
 948  * is used to determine whether to copy pixels that are not in the current pass.
 949  *
 950  * Because 'png_do_read_interlace' (below) replicates pixels this allows this
 951  * function to achieve the documented 'blocky' appearance during interlaced read
 952  * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
 953  * are not changed if they are not in the current pass, when display is 0.
 954  *
 955  * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
 956  *
 957  * The API always reads from the png_struct row buffer and always assumes that
 958  * it is full width (png_do_read_interlace has already been called.)
 959  *
 960  * This function is only ever used to write to row buffers provided by the
 961  * caller of the relevant libpng API and the row must have already been
 962  * transformed by the read transformations.
 963  *
 964  * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
 965  * bitmasks for use within the code, otherwise runtime generated masks are used.
 966  * The default is compile time masks.
 967  */
 968 #ifndef PNG_USE_COMPILE_TIME_MASKS
 969 #  define PNG_USE_COMPILE_TIME_MASKS 1
 970 #endif
 971 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
 972     int display));
 973
 974 #ifdef PNG_READ_INTERLACING_SUPPORTED
 975 /* Expand an interlaced row: the 'row_info' describes the pass data that has
 976  * been read in and must correspond to the pixels in 'row', the pixels are
 977  * expanded (moved apart) in 'row' to match the final layout, when doing this
 978  * the pixels are *replicated* to the intervening space.  This is essential for
 979  * the correct operation of png_combine_row, above.
 980  */
 981 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
 982     png_bytep row, int pass, png_uint_32 transformations));
 983 #endif
 984
 985 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
 986
 987 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
 988 /* Grab pixels out of a row for an interlaced pass */
 989 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
 990     png_bytep row, int pass));
 991 #endif
 992
 993 /* Unfilter a row: check the filter value before calling this, there is no point
 994  * calling it for PNG_FILTER_VALUE_NONE.
 995  */
 996 PNG_EXTERN void png_read_filter_row PNGARG((png_structp pp, png_row_infop row_info,
 997     png_bytep row, png_const_bytep prev_row, int filter));
 998
 999 PNG_EXTERN void png_read_filter_row_up_neon PNGARG((png_row_infop row_info,
1000     png_bytep row, png_const_bytep prev_row));
1001 PNG_EXTERN void png_read_filter_row_sub3_neon PNGARG((png_row_infop row_info,
1002     png_bytep row, png_const_bytep prev_row));
1003 PNG_EXTERN void png_read_filter_row_sub4_neon PNGARG((png_row_infop row_info,
1004     png_bytep row, png_const_bytep prev_row));
1005 PNG_EXTERN void png_read_filter_row_avg3_neon PNGARG((png_row_infop row_info,
1006     png_bytep row, png_const_bytep prev_row));
1007 PNG_EXTERN void png_read_filter_row_avg4_neon PNGARG((png_row_infop row_info,
1008     png_bytep row, png_const_bytep prev_row));
1009 PNG_EXTERN void png_read_filter_row_paeth3_neon PNGARG((png_row_infop row_info,
1010     png_bytep row, png_const_bytep prev_row));
1011 PNG_EXTERN void png_read_filter_row_paeth4_neon PNGARG((png_row_infop row_info,
1012     png_bytep row, png_const_bytep prev_row));
1013
1014 /* Choose the best filter to use and filter the row data */
1015 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
1016     png_row_infop row_info));
1017
1018 /* Finish a row while reading, dealing with interlacing passes, etc. */
1019 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
1020
1021 /* Initialize the row buffers, etc. */
1022 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
1023
1024 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1025 /* Optional call to update the users info structure */
1026 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
1027     png_infop info_ptr));
1028 #endif
1029
1030 /* These are the functions that do the transformations */
1031 #ifdef PNG_READ_FILLER_SUPPORTED
1032 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
1033     png_bytep row, png_uint_32 filler, png_uint_32 flags));
1034 #endif
1035
1036 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
1037 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
1038     png_bytep row));
1039 #endif
1040
1041 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1042 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
1043     png_bytep row));
1044 #endif
1045
1046 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1047 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
1048     png_bytep row));
1049 #endif
1050
1051 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1052 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
1053     png_bytep row));
1054 #endif
1055
1056 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1057     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1058 PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info,
1059     png_bytep row, int at_start));
1060 #endif
1061
1062 #ifdef PNG_16BIT_SUPPORTED
1063 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1064 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
1065     png_bytep row));
1066 #endif
1067 #endif
1068
1069 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1070     defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1071 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
1072     png_bytep row));
1073 #endif
1074
1075 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1076 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr,
1077     png_row_infop row_info, png_bytep row));
1078 #endif
1079
1080 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1081 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
1082     png_bytep row));
1083 #endif
1084
1085 #ifdef PNG_READ_PACK_SUPPORTED
1086 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
1087     png_bytep row));
1088 #endif
1089
1090 #ifdef PNG_READ_SHIFT_SUPPORTED
1091 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info,
1092     png_bytep row, png_const_color_8p sig_bits));
1093 #endif
1094
1095 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1096 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
1097     png_bytep row));
1098 #endif
1099
1100 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1101 PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info,
1102     png_bytep row));
1103 #endif
1104
1105 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1106 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
1107     png_bytep row));
1108 #endif
1109
1110 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1111 PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info,
1112     png_bytep row, png_const_bytep palette_lookup,
1113     png_const_bytep quantize_lookup));
1114
1115 #  ifdef PNG_CORRECT_PALETTE_SUPPORTED
1116 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
1117     png_colorp palette, int num_palette));
1118 #  endif
1119 #endif
1120
1121 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1122 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
1123     png_bytep row));
1124 #endif
1125
1126 #ifdef PNG_WRITE_PACK_SUPPORTED
1127 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
1128    png_bytep row, png_uint_32 bit_depth));
1129 #endif
1130
1131 #ifdef PNG_WRITE_SHIFT_SUPPORTED
1132 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info,
1133     png_bytep row, png_const_color_8p bit_depth));
1134 #endif
1135
1136 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
1137     defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1138 PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info,
1139     png_bytep row, png_structp png_ptr));
1140 #endif
1141
1142 #ifdef PNG_READ_GAMMA_SUPPORTED
1143 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info,
1144     png_bytep row, png_structp png_ptr));
1145 #endif
1146
1147 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1148 PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info,
1149    png_bytep row, png_structp png_ptr));
1150 #endif
1151
1152 #ifdef PNG_READ_EXPAND_SUPPORTED
1153 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
1154     png_bytep row, png_const_colorp palette, png_const_bytep trans,
1155     int num_trans));
1156 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
1157     png_bytep row, png_const_color_16p trans_color));
1158 #endif
1159
1160 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1161 PNG_EXTERN void png_do_expand_16 PNGARG((png_row_infop row_info,
1162     png_bytep row));
1163 #endif
1164
1165 /* The following decodes the appropriate chunks, and does error correction,
1166  * then calls the appropriate callback for the chunk if it is valid.
1167  */
1168
1169 /* Decode the IHDR chunk */
1170 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
1171     png_uint_32 length));
1172 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
1173     png_uint_32 length));
1174 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
1175     png_uint_32 length));
1176
1177 #ifdef PNG_READ_bKGD_SUPPORTED
1178 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
1179     png_uint_32 length));
1180 #endif
1181
1182 #ifdef PNG_READ_cHRM_SUPPORTED
1183 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
1184     png_uint_32 length));
1185 #endif
1186
1187 #ifdef PNG_READ_gAMA_SUPPORTED
1188 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
1189     png_uint_32 length));
1190 #endif
1191
1192 #ifdef PNG_READ_hIST_SUPPORTED
1193 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
1194     png_uint_32 length));
1195 #endif
1196
1197 #ifdef PNG_READ_iCCP_SUPPORTED
1198 PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
1199     png_uint_32 length));
1200 #endif /* PNG_READ_iCCP_SUPPORTED */
1201
1202 #ifdef PNG_READ_iTXt_SUPPORTED
1203 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1204     png_uint_32 length));
1205 #endif
1206
1207 #ifdef PNG_READ_oFFs_SUPPORTED
1208 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
1209     png_uint_32 length));
1210 #endif
1211
1212 #ifdef PNG_READ_pCAL_SUPPORTED
1213 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
1214     png_uint_32 length));
1215 #endif
1216
1217 #ifdef PNG_READ_pHYs_SUPPORTED
1218 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
1219     png_uint_32 length));
1220 #endif
1221
1222 #ifdef PNG_READ_sBIT_SUPPORTED
1223 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
1224     png_uint_32 length));
1225 #endif
1226
1227 #ifdef PNG_READ_sCAL_SUPPORTED
1228 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
1229     png_uint_32 length));
1230 #endif
1231
1232 #ifdef PNG_READ_sPLT_SUPPORTED
1233 PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
1234     png_uint_32 length));
1235 #endif /* PNG_READ_sPLT_SUPPORTED */
1236
1237 #ifdef PNG_READ_sRGB_SUPPORTED
1238 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
1239     png_uint_32 length));
1240 #endif
1241
1242 #ifdef PNG_READ_tEXt_SUPPORTED
1243 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1244     png_uint_32 length));
1245 #endif
1246
1247 #ifdef PNG_READ_tIME_SUPPORTED
1248 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
1249     png_uint_32 length));
1250 #endif
1251
1252 #ifdef PNG_READ_tRNS_SUPPORTED
1253 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
1254     png_uint_32 length));
1255 #endif
1256
1257 #ifdef PNG_READ_zTXt_SUPPORTED
1258 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1259     png_uint_32 length));
1260 #endif
1261
1262 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1263 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
1264     png_infop info_ptr, png_uint_32 length));
1265 #endif
1266
1267 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
1268     png_uint_32 chunk_name));
1269
1270 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1271 /* Exactly as png_handle_as_unknown() except that the argument is a 32-bit chunk
1272  * name, not a string.
1273  */
1274 PNG_EXTERN int png_chunk_unknown_handling PNGARG((png_structp png_ptr,
1275     png_uint_32 chunk_name));
1276 #endif
1277
1278 /* Handle the transformations for reading and writing */
1279 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1280 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr,
1281    png_row_infop row_info));
1282 #endif
1283 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1284 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr,
1285    png_row_infop row_info));
1286 #endif
1287
1288 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1289 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
1290 #endif
1291
1292 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1293 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
1294     png_infop info_ptr));
1295 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
1296     png_infop info_ptr));
1297 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
1298 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
1299     png_uint_32 length));
1300 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
1301 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
1302 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
1303     png_bytep buffer, png_size_t buffer_length));
1304 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
1305 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
1306     png_bytep buffer, png_size_t buffer_length));
1307 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
1308 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
1309    png_infop info_ptr, png_uint_32 length));
1310 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
1311    png_infop info_ptr));
1312 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
1313    png_infop info_ptr));
1314 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
1315 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
1316     png_infop info_ptr));
1317 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
1318     png_infop info_ptr));
1319 PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
1320 #  ifdef PNG_READ_tEXt_SUPPORTED
1321 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
1322     png_infop info_ptr, png_uint_32 length));
1323 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
1324     png_infop info_ptr));
1325 #  endif
1326 #  ifdef PNG_READ_zTXt_SUPPORTED
1327 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
1328     png_infop info_ptr, png_uint_32 length));
1329 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
1330     png_infop info_ptr));
1331 #  endif
1332 #  ifdef PNG_READ_iTXt_SUPPORTED
1333 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
1334     png_infop info_ptr, png_uint_32 length));
1335 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
1336     png_infop info_ptr));
1337 #  endif
1338
1339 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1340
1341 #ifdef PNG_MNG_FEATURES_SUPPORTED
1342 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
1343     png_bytep row));
1344 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
1345     png_bytep row));
1346 #endif
1347
1348 /* Added at libpng version 1.4.0 */
1349 #ifdef PNG_CHECK_cHRM_SUPPORTED
1350 PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
1351     png_fixed_point int_white_x, png_fixed_point int_white_y,
1352     png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
1353     int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
1354     png_fixed_point int_blue_y));
1355 #endif
1356
1357 #ifdef PNG_CHECK_cHRM_SUPPORTED
1358 /* Added at libpng version 1.2.34 and 1.4.0 */
1359 /* Currently only used by png_check_cHRM_fixed */
1360 PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
1361     unsigned long *hi_product, unsigned long *lo_product));
1362 #endif
1363
1364 #ifdef PNG_cHRM_SUPPORTED
1365 /* Added at libpng version 1.5.5 */
1366 typedef struct png_xy
1367 {
1368    png_fixed_point redx, redy;
1369    png_fixed_point greenx, greeny;
1370    png_fixed_point bluex, bluey;
1371    png_fixed_point whitex, whitey;
1372 } png_xy;
1373
1374 typedef struct png_XYZ
1375 {
1376    png_fixed_point redX, redY, redZ;
1377    png_fixed_point greenX, greenY, greenZ;
1378    png_fixed_point blueX, blueY, blueZ;
1379 } png_XYZ;
1380
1381 /* The conversion APIs return 0 on success, non-zero on a parameter error. They
1382  * allow conversion between the above representations of a color encoding.  When
1383  * converting from XYZ end points to chromaticities the absolute magnitude of
1384  * the end points is lost, when converting back the sum of the Y values of the
1385  * three end points will be 1.0
1386  */
1387 PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ));
1388 PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy));
1389 PNG_EXTERN int png_XYZ_from_xy_checked PNGARG((png_structp png_ptr,
1390    png_XYZ *XYZ, png_xy xy));
1391 #endif
1392
1393 /* Added at libpng version 1.4.0 */
1394 PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
1395     png_uint_32 width, png_uint_32 height, int bit_depth,
1396     int color_type, int interlace_type, int compression_type,
1397     int filter_type));
1398
1399 /* Added at libpng version 1.5.10 */
1400 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1401     defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1402 PNG_EXTERN void png_do_check_palette_indexes PNGARG((png_structp png_ptr,
1403     png_row_infop row_info));
1404 #endif
1405
1406 /* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1407 PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr,
1408     png_infop info_ptr, png_infop end_info_ptr));
1409
1410 /* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1411 PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr));
1412
1413 #ifdef USE_FAR_KEYWORD  /* memory model conversion function */
1414 PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr,
1415     int check));
1416 #endif /* USE_FAR_KEYWORD */
1417
1418 #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1419 PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr,
1420    png_const_charp name),PNG_NORETURN);
1421 #endif
1422
1423 /* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1424  * the end.  Always leaves the buffer nul terminated.  Never errors out (and
1425  * there is no error code.)
1426  */
1427 PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos,
1428     png_const_charp string);
1429
1430 /* Various internal functions to handle formatted warning messages, currently
1431  * only implemented for warnings.
1432  */
1433 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1434 /* Utility to dump an unsigned value into a buffer, given a start pointer and
1435  * and end pointer (which should point just *beyond* the end of the buffer!)
1436  * Returns the pointer to the start of the formatted string.  This utility only
1437  * does unsigned values.
1438  */
1439 PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end,
1440    int format, png_alloc_size_t number);
1441
1442 /* Convenience macro that takes an array: */
1443 #define PNG_FORMAT_NUMBER(buffer,format,number) \
1444    png_format_number(buffer, buffer + (sizeof buffer), format, number)
1445
1446 /* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1447 #define PNG_NUMBER_BUFFER_SIZE 24
1448
1449 /* These are the integer formats currently supported, the name is formed from
1450  * the standard printf(3) format string.
1451  */
1452 #define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
1453 #define PNG_NUMBER_FORMAT_02u   2
1454 #define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
1455 #define PNG_NUMBER_FORMAT_02d   2
1456 #define PNG_NUMBER_FORMAT_x     3
1457 #define PNG_NUMBER_FORMAT_02x   4
1458 #define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1459 #endif
1460
1461 #ifdef PNG_WARNINGS_SUPPORTED
1462 /* New defines and members adding in libpng-1.5.4 */
1463 #  define PNG_WARNING_PARAMETER_SIZE 32
1464 #  define PNG_WARNING_PARAMETER_COUNT 8
1465
1466 /* An l-value of this type has to be passed to the APIs below to cache the
1467  * values of the parameters to a formatted warning message.
1468  */
1469 typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1470    PNG_WARNING_PARAMETER_SIZE];
1471
1472 PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number,
1473     png_const_charp string);
1474     /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1475      * including the trailing '\0'.
1476      */
1477 PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p,
1478     int number, int format, png_alloc_size_t value);
1479     /* Use png_alloc_size_t because it is an unsigned type as big as any we
1480      * need to output.  Use the following for a signed value.
1481      */
1482 PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p,
1483     int number, int format, png_int_32 value);
1484
1485 PNG_EXTERN void png_formatted_warning(png_structp png_ptr,
1486     png_warning_parameters p, png_const_charp message);
1487     /* 'message' follows the X/Open approach of using @1, @2 to insert
1488      * parameters previously supplied using the above functions.  Errors in
1489      * specifying the paramters will simple result in garbage substitutions.
1490      */
1491 #endif
1492
1493 /* ASCII to FP interfaces, currently only implemented if sCAL
1494  * support is required.
1495  */
1496 #if defined(PNG_READ_sCAL_SUPPORTED)
1497 /* MAX_DIGITS is actually the maximum number of characters in an sCAL
1498  * width or height, derived from the precision (number of significant
1499  * digits - a build time settable option) and assumpitions about the
1500  * maximum ridiculous exponent.
1501  */
1502 #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1503
1504 #ifdef PNG_FLOATING_POINT_SUPPORTED
1505 PNG_EXTERN void png_ascii_from_fp PNGARG((png_structp png_ptr, png_charp ascii,
1506     png_size_t size, double fp, unsigned int precision));
1507 #endif /* FLOATING_POINT */
1508
1509 #ifdef PNG_FIXED_POINT_SUPPORTED
1510 PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
1511     png_charp ascii, png_size_t size, png_fixed_point fp));
1512 #endif /* FIXED_POINT */
1513 #endif /* READ_sCAL */
1514
1515 #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1516 /* An internal API to validate the format of a floating point number.
1517  * The result is the index of the next character.  If the number is
1518  * not valid it will be the index of a character in the supposed number.
1519  *
1520  * The format of a number is defined in the PNG extensions specification
1521  * and this API is strictly conformant to that spec, not anyone elses!
1522  *
1523  * The format as a regular expression is:
1524  *
1525  * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1526  *
1527  * or:
1528  *
1529  * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1530  *
1531  * The complexity is that either integer or fraction must be present and the
1532  * fraction is permitted to have no digits only if the integer is present.
1533  *
1534  * NOTE: The dangling E problem.
1535  *   There is a PNG valid floating point number in the following:
1536  *
1537  *       PNG floating point numb1.ers are not greedy.
1538  *
1539  *   Working this out requires *TWO* character lookahead (because of the
1540  *   sign), the parser does not do this - it will fail at the 'r' - this
1541  *   doesn't matter for PNG sCAL chunk values, but it requires more care
1542  *   if the value were ever to be embedded in something more complex.  Use
1543  *   ANSI-C strtod if you need the lookahead.
1544  */
1545 /* State table for the parser. */
1546 #define PNG_FP_INTEGER    0  /* before or in integer */
1547 #define PNG_FP_FRACTION   1  /* before or in fraction */
1548 #define PNG_FP_EXPONENT   2  /* before or in exponent */
1549 #define PNG_FP_STATE      3  /* mask for the above */
1550 #define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
1551 #define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
1552 #define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
1553 #define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
1554 #define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
1555
1556 /* These three values don't affect the parser.  They are set but not used.
1557  */
1558 #define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
1559 #define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
1560 #define PNG_FP_NONZERO  256  /* A non-zero value */
1561 #define PNG_FP_STICKY   448  /* The above three flags */
1562
1563 /* This is available for the caller to store in 'state' if required.  Do not
1564  * call the parser after setting it (the parser sometimes clears it.)
1565  */
1566 #define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
1567
1568 /* Result codes for the parser (boolean - true meants ok, false means
1569  * not ok yet.)
1570  */
1571 #define PNG_FP_MAYBE      0  /* The number may be valid in the future */
1572 #define PNG_FP_OK         1  /* The number is valid */
1573
1574 /* Tests on the sticky non-zero and negative flags.  To pass these checks
1575  * the state must also indicate that the whole number is valid - this is
1576  * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1577  * is equivalent to PNG_FP_OK above.)
1578  */
1579 #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1580    /* NZ_MASK: the string is valid and a non-zero negative value */
1581 #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1582    /* Z MASK: the string is valid and a non-zero value. */
1583    /* PNG_FP_SAW_DIGIT: the string is valid. */
1584 #define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1585 #define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1586 #define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1587
1588 /* The actual parser.  This can be called repeatedly, it updates
1589  * the index into the string and the state variable (which must
1590  * be initialzed to 0).  It returns a result code, as above.  There
1591  * is no point calling the parser any more if it fails to advance to
1592  * the end of the string - it is stuck on an invalid character (or
1593  * terminated by '\0').
1594  *
1595  * Note that the pointer will consume an E or even an E+ then leave
1596  * a 'maybe' state even though a preceding integer.fraction is valid.
1597  * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1598  * a valid number.  It's possible to recover from this by calling
1599  * the parser again (from the start, with state 0) but with a string
1600  * that omits the last character (i.e. set the size to the index of
1601  * the problem character.)  This has not been tested within libpng.
1602  */
1603 PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string,
1604     png_size_t size, int *statep, png_size_tp whereami));
1605
1606 /* This is the same but it checks a complete string and returns true
1607  * only if it just contains a floating point number.  As of 1.5.4 this
1608  * function also returns the state at the end of parsing the number if
1609  * it was valid (otherwise it returns 0.)  This can be used for testing
1610  * for negative or zero values using the sticky flag.
1611  */
1612 PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
1613     png_size_t size));
1614 #endif /* pCAL || sCAL */
1615
1616 #if defined(PNG_READ_GAMMA_SUPPORTED) ||\
1617     defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1618 /* Added at libpng version 1.5.0 */
1619 /* This is a utility to provide a*times/div (rounded) and indicate
1620  * if there is an overflow.  The result is a boolean - false (0)
1621  * for overflow, true (1) if no overflow, in which case *res
1622  * holds the result.
1623  */
1624 PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a,
1625     png_int_32 multiplied_by, png_int_32 divided_by));
1626 #endif
1627
1628 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1629 /* Same deal, but issue a warning on overflow and return 0. */
1630 PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr,
1631     png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by));
1632 #endif
1633
1634 #ifdef PNG_READ_GAMMA_SUPPORTED
1635 /* Calculate a reciprocal - used for gamma values.  This returns
1636  * 0 if the argument is 0 in order to maintain an undefined value,
1637  * there are no warnings.
1638  */
1639 PNG_EXTERN png_fixed_point png_reciprocal PNGARG((png_fixed_point a));
1640
1641 /* The same but gives a reciprocal of the product of two fixed point
1642  * values.  Accuracy is suitable for gamma calculations but this is
1643  * not exact - use png_muldiv for that.
1644  */
1645 PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a,
1646     png_fixed_point b));
1647 #endif
1648
1649 #ifdef PNG_READ_GAMMA_SUPPORTED
1650 /* Internal fixed point gamma correction.  These APIs are called as
1651  * required to convert single values - they don't need to be fast,
1652  * they are not used when processing image pixel values.
1653  *
1654  * While the input is an 'unsigned' value it must actually be the
1655  * correct bit value - 0..255 or 0..65535 as required.
1656  */
1657 PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr,
1658     unsigned int value, png_fixed_point gamma_value));
1659 PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value));
1660 PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value,
1661     png_fixed_point gamma_value));
1662 PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value,
1663     png_fixed_point gamma_value));
1664 PNG_EXTERN void png_destroy_gamma_table(png_structp png_ptr);
1665 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr,
1666     int bit_depth));
1667 #endif
1668
1669 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
1670
1671 #include "pngdebug.h"
1672
1673 #ifdef __cplusplus
1674 }
1675 #endif
1676
1677 #endif /* PNGPRIV_H */